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DVA-1 Reflector Development Timeline. Gary Hovey NRC-HIA Dominion Radio Astrophysical Observaotry. Contents. Reflector Project Scope Project Phases and Milestones Key Objectives, Outcomes and Issues by Phase Conclusions. DVA-1 Reflector Project Scope.
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DVA-1 ReflectorDevelopment Timeline Gary Hovey NRC-HIA Dominion Radio Astrophysical Observaotry
Contents • Reflector Project Scope • Project Phases and Milestones • Key Objectives, Outcomes and Issues by Phase • Conclusions DVA-1 Reflector Development TimelineG. Hovey
DVA-1 Reflector Project Scope What are the DVA-1 Goals Pertaining to the Reflector? • Performance Requirement • Reflecting surface that meets maintains it shape over specified operating conditions (wind, temp, gravity). • Cost Requirement • Demonstrate its affordable and has superior cost/performance. • Prototype can be built with available budget and meet performance requirement. • Schedule Requirement • Built within the timeframe of PrepSKA? • Built within the timeframe agreed upon in advance? • Built roughly within the timeframe agreed upon? DVA-1 Reflector Development TimelineG. Hovey
Scope Issues • Budget, resources and schedule are limited. • Requirements are in conflict and need to be prioritized. • What are we designing for? • Schedule? • Which schedule? SKA, Hard or soft deadline? • Cost? • Performance? DVA-1 Reflector Development TimelineG. Hovey
Proposed Reflector Scope Requirements Requirements in Priority • Performance: Must meet SKA performance specifications • Cost: Must be within DVA-1 budget and demonstrate SKA cost/performance • Schedule: Must be adapted to fit performance and cost requirements. DVA-1 Reflector Development TimelineG. Hovey
Proposed Responsibilities and Tasks What does the reflector work include? • Reflector performance and cost key drivers. • Reflector performance and schedule dependent strongly (mainly/mostly) on back-up structure and feed. • Propose reflector consists of: Surface, backup structure, feed & sub-reflector support. These need to be considered together as an integrated whole. • Reflector Interfaces: indexer/receiver box, sub-reflector and turret frame. DVA-1 Reflector Development TimelineG. Hovey
Key Reflector Requirements/Specifications • Performance • Reflector shape and feed/sub-reflector support specs • Dynamic tolerances specs as function wind, gravity and temperature. • Mount interface specs. • Cost • Available budget • Available infrastructure • Available resources and definition of project scope • Schedule • Clear goals and deliverables with achievable deadlines • These need clarity to make progress DVA-1 Reflector Development TimelineG. Hovey
Proposed Reflector Project Phases • Four Phase Project • Concept Design Phase -> Concept Design Review • Preliminary Design Phase -> Preliminary Design Review • Detailed Design Phase -> Critical Design Review • Fabrication Phase -> Fabrication Acceptance • Test Phase -> Project Complete • Clear specifications, objectives and deliverables for each phase are needed to ensure performance, cost and schedule requirements. DVA-1 Reflector Development TimelineG. Hovey
Reflector Concept Design Phase • Objective: Define project based on feasible design concepts. • Duration: 2-3 months once requirements/specifications set. • Outcomes • Concept design • Based mainly on estimation, calculation and simulation • Feasible design that meets overall performance, cost and schedule requirements • Risk items identified • Baseline project plan including: • Initial WBS, costs and schedule • Risks: technical, cost, schedule • Plan to address risks DVA-1 Reflector Development TimelineG. Hovey
Key Concept Design Issues • Need to define surface shape specifications • What diameter: 12m or 15m? At CoDR? Now?? • What antenna pattern? What is optimized? • Aeff • Aeff/Tsys • Near and far sidelobe response • Symmetry, stability, uniformity • Need to understand calibration, imaging and computing impact • Select or defer backup structure approach to prelim design? • To what extent are PAFs considered? • Need clarity on design goals: Performance, budget, schedule? • Need clarity on available budget and constraints. • CoDR can’t be done without these issues resolved. DVA-1 Reflector Development TimelineG. Hovey
Reflector Preliminary Design Phase • Objectives • Sketched out design in non-risk areas • Detailed design/studies in riskier areas • Duration: 2-3 months once CoDR complete • Outcomes needed • Preliminary design • Materials selected and their performance known • Risk items addressed • Based on calculation, simulation and measurement • Technical risk low • Updated project plan • Schedule and cost risk quantified • Detailed design plan well defined • Fabrication and test plan well understood. DVA-1 Reflector Development TimelineG. Hovey
Reflector Preliminary Design Activities • Material studies/testing • Finalize composite materials • Select/refine backing structure • Refine feed support • Possibly, procure mold(s) as soon as surface defined. DVA-1 Reflector Development TimelineG. Hovey
Reflector Detailed Design Phase • Goal: Fully specify design, as well as, fabrication and test plans • Time needed: 4-6 months once PDR complete. • Outcomes needed • Fully specified design. • Risks low: Costs, schedule well determined. • Detailed fabrication and acceptance plan(s) • Activities, WBS, deliverables, costs and schedule • Detailed test plan DVA-1 Reflector Development TimelineG. Hovey
Detailed Design Issues • This is mainly a fill in the blanks phase. • To what extend do we validate dynamics (wind, temp, resonance)? Schedule vs cost risk • How much design margin is carried? • Material cost vs performance and schedule risk • Can molds be ordered before CDR? Schedule vs cost risk DVA-1 Reflector Development TimelineG. Hovey
Reflector Fabrication Phase • Objectives: fabricate/assemble reflector, back-up structure, feed/sub support. • Duration: 6-9 months (not including setup/procurement) • Outcomes • Sub-assembly fabrication and acceptance complete • Reflector surface • Backup structure • Feed/sub support • Assembly complete and ready for test on mount DVA-1 Reflector Development TimelineG. Hovey
Fabrication Phase: Issues • Lead time for procurement of materials • Lead time for preparing site for fabrication • What facilities on-site can be used? • Site regulation and procedure issues • Schedule and cost overheads due to the location • Costs magnified if project delayed • Clean-up costs DVA-1 Reflector Development TimelineG. Hovey
Reflector Test Phase • Objectives: Determine reflector assembly performance • Duration: 2-4 months • Outcomes • Reflector metrology tests • Over gravity, temp, wind • Simulated antenna pattern response • Measured antenna pattern and holography measurements DVA-1 Reflector Development TimelineG. Hovey
Reflector Test Phase Issues • Separating dynamic reflector performance from the mount. • Testing over temperature extremes difficult • Testing over wind conditions/requirements difficult • Schedule and cost overheads due to the location DVA-1 Reflector Development TimelineG. Hovey
Timeline 2010 2011 2012 Buy Molds DVA-1 Reflector Development TimelineG. Hovey
Conclusions • Reflector project reasonably complex. • Need to better define scope and responsibilities • Number of requirements/issues need to be address/resolved. • Project plan, design phases and reviews needed • These would inform key decisions. DVA-1 Reflector Development TimelineG. Hovey